This invention relates to oil soluble hydroxylated olefin polymers, e.g., the hydroxylated reaction products of halogen containing polymers will polyol metal salts, a method for their preparation, and to compositions comprising a major proportion of a fuel or lubricant and a minor proportion of said hydroxylated polymer as a sludge dispersant and/or V.I. improver. More preferably this invention relates to copolymers of ethylene and higher .alpha.-olefins and to terpolymers comprising ethylene, a higher .alpha.-olefin and a nonconjugated diolefin, which have been halogenated or hydrohalogenated, and then hydroxylated by reaction with a metal salt of a polyol. Alternatively, in the synthesis of the terpolymer, the nonconjugated diene may be replaced in whole or in part by an acyclic or alicyclic halo-olefin to thereby directly give the halogen containing polymer which is then reacted with said metal salt.
2. Prior Art
Compositions comprising polymeric or high molecular weight materials which incorporate hydroxyl groups have been described in U.S. and foreign patents as dispersants and/or viscosity index improvers for fuels and/or lubricants. For example:
U.S. Pat. No. 3,621,004 discloses lubricant additives containing hydroxylated polymers formed by copolymerizing ethylene, alkyl (C.sub.8 -C.sub.20) methacrylates, and .beta.-hydroxyethyl methacrylate as viscosity index improvers and sludge dispersants.
U.S. Pat. No. 3,687,849; German Pat. No. 1,929,811; and Canadian Pat. 728,709, disclose lubricant compositions containing hydroperoxidized olefin copolymers with grafted hydroxy monomers such as allyl alcohol, .beta.-hydroxyethyl methacrylate, and vinyl acetate (hydrolyzed subsequently to vinyl alcohol groups) which act as ash free sludge dispersants.
U.S. Pat. No. 3,642,633 discloses lubricant compositions containing terpolymers of vinyl toluene, a mixture of lauryl and stearyl methacrylate, and .beta.-hydroxyethyl methacrylate; or terpolymers containing methacrylic acid ethoxylated to .beta.-hydroxyethyl methacrylate; which terpolymers are pour depressants, viscosity index improvers, and sludge dispersants.
U.S. Pat. No. 3,888,067 discloses lubricant additives containing hydroxylated ethylene-propylene rubbers made by reduction of hydroperoxidized (by a hydroperoxide) polymer.
U.S. Pat. No. 3,381,022 discloses lubricant additives made by the reaction of alkenyl succinic anhydride and polyalcohols as sludge dispersants.